Facebook has acquired SportStream, a San Francisco startup that analyzes mentions of sports on social media sites like Twitter, Facebook and Instagram. It sells that data to media sites or sports teams to use on their websites, or simply to track what people are saying.

Terms of the deal were not disclosed but we know that SportStream raised at least $3.5 million when it was founded in 2012 and was backed by Microsoft co-founder Paul Allen's venture firm, Vulcan Capital.

Neither the announcement by Facebook, nor the one by SportStream explains what Facebook plans to do with the technology, except that it will use it to better connect Facebook with sports fans.

According to LinkedIn, the startup employed about a dozen people. Facebook's post says that its welcoming the SportStream folks to its Menlo Park campus.

Here's the full announcement from SportStream:

Joining Facebook

We’re excited to announce that Facebook has agreed to acquire SportStream.

We set out 18 months ago to help fans better connect around all the best moments in sports. We made it our mission to deliver them the best social content, stats, news and more around games, favorite teams and players in real-time. We’ve made significant progress, especially through our relationships with major sports media companies and teams. The tools and services developed by our small team have helped some of the biggest names in sports leverage social media in exciting new ways for their fans. Joining Facebook provides an amazing opportunity for us to greatly expand on our original vision.

Facebook sees the value in our technologies and team, and we’re excited to be a part of their continued investment in their platform. With this next step for SportStream, we’ll have greater resources to continue to do what we do best. We expect to make an impact on the more than 1 billion people who use Facebook as well as the many valued sports media businesses and professionals, teams, leagues and players that use Facebook to better connect with fans. At Facebook, we will continue delivering great experiences with our existing partners and actively work with them on transition planning. And we’ll be scaling and further developing tools and resources to help many, many more partners going forward.

We’re incredibly grateful to those who have supported us and been a part of the SportStream story. We’re especially appreciative of the ongoing support from our families, the team at Vulcan Capital, our partners and all the friends of the company that have been behind us along the way. We’re looking forward to the road ahead at Facebook!